The present invention relates to an apparatus for assisting percutaneous light beam guided surgical activity into a human or animal body based on calculated craniocaudal and transverse related insertion angles for an injection instrument, such as a syringe needle or biopsy means, relative to a target inside said body, said apparatus having means for providing at least a laser beam from a laser device in a laser unit for assisting guided instrument injection into said body, said laser unit having a housing being positionable along a laser unit supporting means and lockable thereto, said laser unit having means for adjusting the direction of said laser beam relative to said body based on said calculated insertion angles.
Prior art apparatus of this type are known from e.g. U.S. Pat. No. 5,628,327 (Unger et al) and U.S. Pat. No. 6,021,342 (Brabrand).
U.S. Pat. No. 5,628,327 describes a device which is complicated to operate due to risk of angle errors relative to craniocaudal direction and transverse direction as well as direction of gravity.
U.S. Pat. No. 6,021,342, relative to which the present invention is an improvement, provides an apparatus for manually adjusting insertion angles. The apparatus has no means for compensating any laser device direction deviations away from direction of gravity, which in certain cases could cause insertion angle problems.
The present invention intends to provide an apparatus which based on calculated, craniocaudal and transverse related insertion angles for the injection instrument is capable of fully automatically directing the laser beam of the laser device along the correct laser beam direction, thus indicating in the first hand the insertion point on the body of the patient, and secondly upon placing the point of the instrument needle thereat, pointing the beam at a rear end of the instrument for the laser beam guided insertion. Further, based on the set calculated instrument insertion angle values, provided from an input device, the insertion angle values being calculated by e.g. a computed tomography unit or a magnetic resonance tomography unit, it is the intention of the invention that the apparatus is able of using such input values to cause the laser device to provide accurately the positioning of the laser beam without any risk of errors caused e.g. by errors due to deviations from directions of gravitation of the laser unit housing.
According to the invention, the apparatus comprises within said laser unit housing:
first attachment means on said laser unit housing for rotatably supporting a first rotation member of said laser unit,
first rotation means attached to said first attachment means for rotating said first rotation member relative to said first attachment means about a first rotation axis,
second attachment means attached to said first rotation member for rotatably supporting a second rotation member, said second rotation member having a second rotation axis at right angles to the first rotation axis,
second rotation means mounted on said first rotation member for rotating said second rotation member relative to said second attachment means,
first and second inclinometer supporting means mounted at right angles to each other and attached to a surface of said second rotation member at right angles thereto,
said laser unit having said laser device attached to said second rotation member in such a way that the laser beam is along an axis intersecting an intersection point between said first and second rotation axis and at right angles thereto,
first inclinometer means installed on said first inclinometer supporting means and second inclinometer means installed on said second inclinometer supporting means, said inclinometer means providing signal values as a function of two- or three dimensional orientation directions of said laser unit housing relative to direction of gravitation,
first and second encoder means cooperative with said first and second rotation means, respectively for feedback of rotary position information thereof, and comparator means for comparing set calculated instrument insertion angle values, provided from an input device, with encoder signal values derived from said feedback information and said inclinometer signal values, said comparator means inhibiting an operation of said first and second rotation means when said encoder signal values and said inclinometer signal values reach threshold values, respectively related to said set insertion angle values and direction of gravitation.
According to the invention a line laser unit having a line laser device is provided, said line laser device providing a laser beam created line for aligning said laser unit housing relative to a craniocaudal direction of a movable bed supporting said body. Thereby, it may be established that e.g. a substantially horizontal laser unit supporting means is extending in direction exactly transverse to said craniocaudal direction. Suitably, said laser device is mounted on said first or second inclinometer supporting means. Further, said line laser device can be mounted on said first or second inclinometer supporting means. Preferably, but not necessarily, said laser device and said line laser device are mechanically rigidly interconnected.
In one embodiment of the present invention, said first and second rotation members have suitably a fixed radius of curvature over at least a substantial part of a circumference thereof, respectively, wherein said first and second rotation means each comprises an electric motor and a shaft thereof, said shaft capable of being in a rotational, frictional engagement with at least a substantial part of said circumference. In order to provide for such an embodiment, said shaft may be provided with a friction creating material. As an alternative or as an added feature, said substantial part of said circumference may be provided with a friction creating material.
Suitably, said frictional engagement is adjustable or maintained through said stepper motor shaft resiliently bearing against said substantial part of the circumference.
In an alternative, said first and second rotation members have a fixed radius of curvature over the full circumference thereof, respectively, wherein said first and second rotation means each comprises an electric motor and a shaft thereof, said shaft capable of being in rotational, frictional engagement with a belt in contact with a substantial part of said circumference.
In a further alternative, said first and second rotation members have a fixed radius of curvature over at least a substantial part of a circumference thereof and have gear teeth extending therealong, respectively, wherein said first and second rotation means each comprises an electric motor and a shaft thereof, said shaft having a gear, capable of being in rotational, frictional engagement with said gear teeth. In still another alternative, said first and second rotation members are each directly connected to a stepper motor shaft.
Suitably, said first and second inclinometer supporting means are circuit board members mounted at right angles to each other and attached to a surface of said second rotation member at right angles thereto, one of said circuit board members having hole means for laser beam exit from said laser device.
Said line laser device is suitably attached to said second rotary member or to one of said inclinometer supporting means.
Said electric motor means is suitably a stepper motor.
In another aspect of the invention, the apparatus further comprises releasable brake means within said laser unit housing, said brake means being in the form of roller means rotatably bearing against and position-fixable relative to a profiled face of said laser unit housing supporting means, and position adjustment means for fine adjustment for a position of said laser unit housing on said supporting means.
In still a further embodiment said laser unit housing supporting means comprises a movable base member, being position lockable relative to a floor, an upright, first housing supporting member extending upwardly from said base member, and a second housing supporting member extending from a top of said first housing supporting member at right angles thereto, and a curved transition member extending between said first and second laser unit housing supporting members for supporting the laser unit and its housing in movement between said first and second head supporting means, whereby said laser unit housing is movable along said first and second head supporting members and selectively lockable thereto.
Suitably said first laser unit housing supporting member is pivotable about its vertical axis relative to said base member, and lockable thereto.